ACR NI-RADS Committee 2018 consensus recommendations for standard imaging surveillance after treatment for head and neck squamous cell carcinoma with adaptation (*) to allow for surveillance MRI. 

1)	PET and contrast-enhanced CT (CECT*) at 8 to 12 weeks after completion of definitive therapy to establish 
a post-treatment baseline

2)	If 8-to-12-week imaging is negative for recurrence, then CECT* alone or PET and CECT* 6 months later:
a.	If 6-month CECT* alone is performed and negative, then repeat CECT* 6 months later
b.	If PET and CECT* are performed at 6 months and both negative, then no additional surveillance imaging is required

3)	If 12-month CECT* alone is performed and negative, then CECT* neck and chest 12 months later
*MRI without and with gadolinium contrast may replace CECT for those treated neoplasms for which surveillance MRI is preferable to CT